Hazardous debris is often generated during industrial maintenance, spill response, and building decontamination projects. Such debris can include piping, pumps, valves, duct work, process tanks, wooden and concrete flooring, spill control booms, personnel protective equipment (PPE) and an almost infinite variety of other items. In terms of waste disposal, debris is defined as a solid material that has a particle size exceeding a 60 mm and that is a manufactured object, plant or animal matter, or natural geologic material. Contaminated soil and process wastes are not debris. In order to qualify for debris treatment standards, any mixture of debris and process waste must be composed primarily of debris, by volume, based upon visual inspection.
Generally, waste materials and debris are placed in rolloff boxes, dumpsters, waste carts, railcars, dump trucks and other conventional transportable containers, and transported therein to an appropriate site for disposal. Disposal sites are typically landfills, such as sanitary, industrial or hazardous waste landfills. While these known transportable containers may be suitable for some types of waste materials, they are unsuitable for many others. For example, hazardous debris may not be safely disposed by means of these known containers.
The United States Environmental Protection Agency (USEPA) treatment standards for hazardous debris as set forth in 40 CFR §268.45 provides for alternative treatments for debris prior to landfill disposal. Among these alternative treatment standards are immobilization technologies that include macroencapsulation and microencapsulation.
The technology of macroencapsulation is described in the Code as “Application of surface coating materials such as polymeric organics (e.g., resins and plastics) or use of a jacket of inert inorganic materials to substantially reduce surface exposure to potential leaching media.”
The performance and/or design and operating standard for macroencapsulation is described in the Code as “Encapsulating material must completely encapsulate debris and be resistant to degradation by the debris and its contaminants and materials into which it may come into contact after placement (leachate, other waste, microbes).”
The technology of microencapsulation is described in the Code as “Stabilization of the debris with the following reagents (or waste reagents) such that the leachability of the hazardous contaminates is reduced: (1) Portland cement; or (2) lime/pozzolans (e.g., fly ash and cement kiln dust). Reagents (e.g., iron salts, silicates, and clays) may be added to enhance the set/cure time and/or compressive strength, or to reduce the leachability of the hazardous constituents.”
The performance and/or design and operating standard for macroencapsulation is described in the Code as “Leachability of the hazardous contaminates must be reduced.” This reduction in leachability requires that intimate contact occur between the virgin or waste reagents and the surfaces contaminated by hazardous wastes. This restricts the application of microencapsulation for many commonly encountered debris types, such as piping, pumps, valves, ductwork, etc. where the generator or contractor is unable or unwilling to expose the surfaces for purposes of reagent contact. Also, this limits the amount of reagent addition at the Resource Conservation and Recovery Act (RCRA) hazardous waste Treatment Storage or Disposal facility (TSD), or else the RCRA TSD has to off-load and reload the rolloff box, in some cases making two or more boxes out of one after reagent addition.
As noted above, macroencapsulation has a performance standard that the debris must be completely encapsulated and the encapsulating material must be resistant to degradation by the debris, its contaminates, leachates and other waste in the landfill, and microbes. Standard rolloff box liners do not meet this performance standard, and much macroencapsulation is being done at the RCRA TSD land disposal facility by virtual of addition of concrete to meet this performance standard. If concrete were added at the collection site, the resulting rolloff box would exceed legal weight limits and thus not be able to be moved on public roadways.
The use of conventional rolloff boxes with hazardous debris would not be acceptable because the rolloff boxes do not microencapsulate or seal the hazardous debris. Yet, the use of conventional transportable waste containers, such as rolloff boxes, is highly desirable from the standpoint of transporting waste material such as debris, to the eventual disposal site.
In addition to the problems associated with collecting waste debris from industrial sites, spill sites, decontamination projects, etc., and safely transporting the waste debris to an appropriate site for treatment and disposal, often the waste debris has to be offloaded and sorted for proper identification, treatment and disposable. For example, an industrial site spill caused by processing equipment failure may produce waste debris in the form of chemical contaminated broken processing equipment. Cleanup of the spill can generate additional debris in the form of chemical (neutralizing compounds, cleaning materials, etc.) contaminated cleanup equipment, including protective clothing, booms, hoses, etc. In addition to this debris that is directly associated with the chemical process and cleanup equipment, contaminated objects or structures proximal to the spill site can include furniture, fixtures, shelving, bins, flooring, etc. all of which may be collected as waste debris from an industrial site.
If the waste debris is not properly classified or treated when collected, it may have to be offloaded and sorted. The offloading and sorting of waste debris is a time-consuming process that requires containment facilities and exposes workers to addition hazards.
The present invention provides methods and apparatus for safely disposing of waste materials which is an improvement over present methods which addresses the limitations of both microencapsulation and macroencapsulation.